I have a working villager breeder and I'm building a trading hall. I need to hold onto my villagers until they're adults otherwise they can escape the hall. I was thinking of putting them in somekind of loop until they've grown up but I can't find a way of detecting the difference. Observers can't see babies or adults (at least, not when they're in minecarts), trip wires don't detect either, as they go past in a minecart. Is there a standard pattern for doing this?


If you make a water elevator with signs, baby villagers can't climb the elevator, so they are forced to grow up into adults before they can interact with the elevator.

So if you make an elevator inside the hall, it should block the babies from escaping.


I can't guarantee it will work on Bedrock - best test it in creative first - but Gnembon has developed an ingeniously simple and easy to build device that holds baby villagers until they grow up.

This is the device as implemented as a part of his villager breeder: enter image description here

and this is the same, stand-alone and with side walls glass replaced with barrier blocks. Buttons were placed behind water source blocks - all remaining water is flowing. enter image description here

The idea is ingenuious in its simplicity. The short bubblevator (with the standard push-pull features for pulling mobs into the water column - a wall block, and a gap for water to flow in) ends with a glass block 'cap', so any babies will get trapped under the glass block. (don't worry, they won't drown - bubble column provides air.) The moment they grow, their feet remain on the same level, but their heads glitch into the glass block above - it stops blocking them, so the bubblevator is able to push them even higher. Then they are caught by the water stream above and pushed through the open fence gate into the collection area.

  • unless I did something wrong this doesnt work in bedrock imgur.com/a/KfOPrx9 – Penguin Feb 2 at 19:12
  • @Penguin If all the blocks in the bubble column are sources (child stuck right under the "ceiling" then that means it doesn't work on Bedrock... :( (also: it takes only children in, and ejects them when they've grown; it won't separate adults from children on the incoming stream. If you just spawned an adult, it won't work) – SF. Feb 2 at 19:28
  • nvm, it works then! :) – Penguin Feb 5 at 1:01

Make a structure like this: Upper Underside: Underside

The benefit of this is that if for some reason an adult comes through, it will trigger immediately.

  • I don't see how this can work..How do you place rails on a bottom slab? – serialhobbyist Feb 2 at 18:51
  • @serialhobbyist no the minecart would go along rails and then fall onto the bottom slab. You can then use a piston or something to drop them or push them somewhere when needed – Penguin Feb 2 at 19:01
  • Still not with you. I'm trying to detect when babies become adults so that I can ship them off to my trading post. I know how to get them out when they get there. It's how to make sure I don't send a baby to the trading post that's the issue,. – serialhobbyist Feb 4 at 16:10
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    @serialhobbyist I've added screenshots, see if those help you understand – Penguin Feb 5 at 0:59
  • @serialhobbyist oh nvm just saw the accepted answer and if that works its much simpler, nvm, I'll still leave mine here because why not :) – Penguin Feb 5 at 1:03

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